Electric switch



. JNVENTOR I71? v10 H- NERO A. H. NERO ELECTRIC SWITCH Filed Nov. '7,1922 III" Patented Dec. 16, 1924.

UNITED STATES PATENT OFFICE.

ARVID H. NERO, NEW BRITAIN, CONNECTICUT, ASSIGNOR TO THE ARROW ELECTRICCOMPANY, OF HARTFORD,

NEGHCUT.

CONNECTICUT, A COItLPORATION- OF CON- ELECTRIC SWITCH.

Application filed November To all whom it may concern:

Be it known that I, Anvn) H. Nnao, a citizen of the United States ofAmerica, residing at New Britain, in the county of a Hartford and Stateof Connecticut, have invented certain new and useful Improvements inElectric Switches, of which the following is a specification.

My invention relates to electric switches,

1 and particularly to switches of the toggle mechanism type. The objectof my invention is to provide a simple and efic ent means for posit1velyinsuring the operation of the toggle n the accompanying drawings I Fig.1 is a longitudinal section through a switch in which my invention isembodied in one form;

Fig. 2 is a partial longitudinal section 29 similar to Fig. 1, butshowing the toggle members in difierent operative position;

Fig. 3 is a section on the line 33, Fig. 2; Fig. 4 is a droppedperspective of a spring guide pin and associated parts;

935 Fig. 5 is a broken side elevation of a toggle switch of difierentgeneral construction from that shown in Fig. 1, but illustrating theapplication of the present invention thereto:

gig. 6 is a section on the line 6-6, Fig. 5;

an i

Fig. 7 is a perspective of the kick-01f element of modified form shownin this construction.

It is well known that in electric switches using a toggle mechanism,there is always danger that the contact blade of the switch may becomefrozen to the stationary contacts of the switch, due to oxidation of theengaging surfaces, or from other causes.

When this occurs, a reversal of the position of the toggle spring failsto effect the throw of the switch bar, since the spring has notsufiicient biasing efiort to overcome the engagement between the frozensurfaces. It is thus impossible to open the switch by the manipulationof the switch-operating means. Dangerous conditions may thus arise whichit is impossible to alter, save by opening the circuit at some otherpoint.

I am aware that positive kick-ofi devices have previously been su gestedfor meeting this dlfiiculty, but these evices have necessi- 7, 1922.Serial No. 599,502.

tated special constructions of the rock lever, switch bar yoke, or otherelement of the switch mechanism, thus adding to the expense of theconstruction. By the present invention 1 supply a positive kick-offdevice which may be applied to any standard switch of the toggle type,in which a guide pin for the toggle-operating spring is utilized.

The invention may be applied to toggle switches of any type, but for thesake of explanation I have illustrated in Figs. 1 to 40f theaccompanying drawings, a flush switch of the general construction shownin the copending application of William H. Harrington, filed November 7,1922, Serial No. 599,499. In a switch of this type the mechanism ismounted in a cup-shaped insulating base 10, in the chamber 11 of whichare the fixed contacts 12, 13, with which cooperates the switchbar 14.The latter is carried by a yoke 15 pivoted on the frame 16 and actuatedby the toggle spring 17 through the rocker 18 in well understood manner.The switch spring 17 bears at the rocker end against a plate 19, thelugs 20 on which are engaged by the arms of the rocker. Passing throughthe hole 21 in this plate is the guide pin 22 for the switch spring 17.At its lower end the guide pin has a head 23 which extends through ahole 24 in the cross bar of the yoke 15 against which the marginal lugs25 of the pin bear. In the present construction, the guide pin 22 is ofrectangular section, and is struck from sheet metal.

The throw of the switch bar yoke 15 is limited by the abutments 26 and27, between which it oscillates. In the present construction theabutments 26 and 27 are formed by downwardly angled lugs from the webs28 and 29 of the switch frame 16 which overlies the supporting shoulders30 and 31 upstanding from the bottom of the cup-shaped insulating body10 of the switch. The present kick-ofi device cooperates with theabutment members, of whatever nature, between which the yoke plays, andis operated by the angular movement of guide-pin 22 incident to theactuation of the rocker 18.

In the form here shown the kick-off device comprises a washer 32 piercedto snugly fit the spring guide pin 22 and forming an abutment againstwhich one end of the switch spring 17 bears. The washer 32 is providedwith laterally extending pairs of legs 33 and 34 on opposite sides ofthe pin 22. As will be observed in Fig. 1, the legs 33 on the side ofthe washer 32 do not bear against the abutment 26 when the switch is atrest. Their length and position is such that on the throw ofthe switchyoke, the latter, and not the lugs 33, impinges against the abutment.The legs 33 of the washer are thus relieved from any shock of impact.When, however, the rocker 18 is rocked on its axis, the end of thespring guide pin 22 engaged thereby changes its angular position withrespect to the switch bar yoke15 since it swings on its lugs 25. Thechange in angular position of the pin brings the laterally projectinglegs 33 of the washer 32 into ongagement with the abutment 26, and theengaging ends of the legs now become a fulcrum and the pin 22 becomes alever of the first class, to one end of which power is positivelyapplied by the rock lever, while its other end engages the yoke 15 andpositively forces the latter away from the abutment 26. This angulardisplacement of the yoke forces the switch bar 14 positively out ofengagement with the fixed contacts 12 and 13, and thus assures the freeaction of the latter under the-biasing efiort of the spring 17 as therocker end of the latter is shifted across the axis of oscillation ofthe yoke. Obviously the same action occurs on the opposite stroke of theswitch when the bar is to be moved to circuit-closing position.

In Figs. 5, 6 and 7 the same idea is applied to a switch mechanism inwhich the insulating body 35 of the switch is of different shape, andthe elements of the switch frame and switch mechanism as a whole is of amore usual type of construction. In this form the frame comprises sideplates 36 which may be downwardly angled from the supporting member 37,and the switch-bar yoke 38 plays between lugs 39 and 40 at the lower endof the frame plates. The rocker 41 operates the bearing plate 42 at oneend of the switch spring in an analogous manner to that first described,shifting it across the axis of oscillation 43 of the switchbar yoke 38.The difference in construction of the kick-off washer 32 is merely thatincident to the different type of abutments 39 and 40 between which theswitch bar yoke oscillates. Thus, the lugs 44 and 45 are of diflerentshape and spacing from those of the washer 32 first described. Theiroperation upon the actuation of the rocker is precisely the same,however.

It is clear that instead of adding a washer to the spring pin to efi'ectthe kick-off operation, thekick-ofi legs 33, 34 or 44, 45 may be formedas lugs integral with the guide pin 22 itself. Or when the pin has asliding engagement with the switch-bar yoke, instead of with the rocker,and is forced downward through the yoke on the actuation of the rocker,a cam-llke abutment may be arranged in the path of the rojecting end ofthe pin which will cause t e latter to exert a like positive freeingeffort on the switch-.

bar .yoke. Other ways of accomplishing the result will readily occur tothose dealing with the problem, but so far as I am aware, no one hasheretofore used the sprin guide pin to effect this action. The particuar construction shown is merely a convenient one which may be used withstandard spring guide pins, but is by no means intended to illustratethe only possible embodiment of the underlying thoughts of what I claimas my invention.

I claim I 1. In an electric switch, a rocker, means angularlydisplaceable with respect thereto to actuate the rocker, a pivotedswitch bar member, .a spring interposed between the rocker and switchbar member and adapted to be shifted at its rocker end across the axisof oscillation of the switch bar member on the actuation of the rocker,a spring guide pin engaging the rocker and switch contact member, aspring abutment member on said pin, and a fixed abutment engaged by saidspring abutment member during the oscillation of the rocker and servingto positively initiate the throw of the switch bar member.

2. In an electric switch, a pivoted rocker, a pivoted switch bar member,an interposed switch spring, an abutment therefor having a pivotedengagement with the rocker, a spring guide pin having a slidingengagement with said abutment and an operating engagement with theswitch bar member, a fixed abutment and a cam member engaged by saidguide pin and moved into engagement with said abutment to positively1n1tiate the throw of the switch bar member on the oscillation of therocker.

3.- In an electric switch, a rocker, a pivoted switch bar yoke, aninterposed operating spring, a flat metal spring guide pin engaging theswitch bar yoke, and a washer mounted on said pin and held againstangularvdisplacement with respect thereto, together with a fixedabutment engaged by said washer on actuation of the rocker to positi elyinitiate the throw of the switch bar.

4. In an electric switch, a rocker, a pivoted switch bar yoke, aninterposed operating spring, a fiat metal spring guide pin en aging theswitch bar yoke with limited reedom of angular play therein, and awashermounted on said pin and held against angular displacement with respectthereto, together with a fixed abutment engaged by said washer onactuation of the rocker to ]positively initiate the throw of the switch5. In an electric switch, a rocker, a pivoted switch bar yoke, a pivotedabutment member engaging the rocker, a spring guide pin passing freelythrough said abutment member and having lugs intermediate its ends andengaging the switch bar yoke, a washer slotted to afford a snugengagement with the pin and resting in adjusted position against thelugs thereon, a switch spring interposed between said washer and theabutment pivoted on the rocker, together with a fixed abutment adaptedfor engagement by said washer to positively initiate the throw of theswitch bar yoke on the actuation of the rocker.

6. In an electric switch, a rocker, a switch bar yoke pivoted on anindependent axis, a switch spring interposed between the rocker andswitch bar yoke and shiftable at its rocker end across the axis ofoscillation of the switch bar yoke, a spring guide pin positivelyengaged with the switch bar yoke, a fixed abutment, and means associatedwith the switch bar pin engaging said abutment and serving to positivelyinitiate the throw of the switch bar on the operation of the rocker.

In testimony whereof I have signed my name to this specification.

ARVI'D H. NERO.

